Some time ago, I written a simple spell for cleansing/recharging crystals, amulets, etc. This is a method I use. There are many ways to do so. You don't need to follow exactly what I've written. You don't have to start on the full moon as I usually do. You can change the ritual to however suits you best.
As for The Devil card, most of the time, I associate it with the concept of being trapped, whether in relationships, careers , etc. They are bound my materialistic things but are never satisfied. Perhaps your friend may need to re-evaluate their life, see if they are truly happy with everything. Do they feel trapped? Are they depressed? Are they materialistic? Tarot has a beautiful way of advising us on how to improve ourselves. The future is never set in stone. I believe the key to happiness is consistent positive thinking. If your friend is not usually a positive thinker, perhaps if she changes that mindset, she may feel happier and free.